Formed metal parts and in particular formed sheet-metal parts are manufactured in multi-component forming presses by deep drawing, restriking, folding, trimming, etc., involving different forming tools.
For the configuration of metal-forming tools (for example, punches, dies, and blank holders), as well as for the configuration of metal-forming processes (for example, tool forces, draw beads, lubrication, shape, and material for the sheet-metal blank), CAD/CAE (computer-aided design/computer-aided engineering) programs are utilized. These simulate and model, respectively, a metal-forming process and in particular a sheet-metal-forming process by means of finite elements on the basis of simulation parameters. Simulation parameters describe                the geometry or shape of the forming tools utilized in the metal-forming process,        process parameters or metal-forming parameters, such as the lubrication, processing forces, drawbeads, etc.        material parameters of the material being formed, such as thickness, elastic properties, yield and hardening behaviour, physical characteristics etc.        
The simulation parameters together with the geometry of the part in the desired (target) state shall be called input parameters. They comprise the parameters that can be influenced by the designer of the forming process and that can be varied in order to optimize the process.
The simulation programs create, by numerical simulation, result values comprising a description of the geometry of a sheet-metal part after the forming process as well as the distribution of state variables, such as elongations and stresses in the formed sheet-metal part. They also may calculate, from the result values, values of certain characteristic variables, called performance variables, which express a quality of the formed sheet-metal part. Both the state variables and the performance variables considered are defined over the material of the sheet-metal part. That is, each material point of the part (or, in a simplified view, each surface point of the part) is associated with a particular, local value of each state variable and the performance variable. Henceforth, state variables and performance variables shall be subsumed by the term “local property variables”. Different types of performance variables and visual representations of the result values and performance variables can be computed and displayed in a post-simulation analysis. Correspondingly, further sets of parameters are used to control the numerical simulation itself (control parameters) and to control different types of post-simulation analysis (analysis parameters).
The values of selected ones of state variables or performance variables are superimposed on a visualisation of a 3D-model of the formed part. This takes place, for example, in a colour contour depiction by colouring the model in every point of the part, respectively, of its surface in accordance with the values of one or more of the variables chosen.
An important task when designing the geometry of the part and defining the simulation parameters is to detect problem zones of the part in which the forming process may cause the finished part to be of lower quality than desired. For example, the material may be stretched too much and exhibit cracks or tears, develop wrinkles, surface lows or grooves, not be sufficiently stretched, exhibit shape deviations due to springback, etc. Depending on the geometry of the part and the simulation parameters, different problems appear in different zones of the part and have to be taken into account during part and simulation parameters design. Typically, the simulation parameters (thus, the geometry of the part and/or the process parameters and/or the material parameters) are adapted iteratively, between simulation runs of the forming process, until the overall result is satisfactory. There is a need to assist users in this process.
In the article “Siemens PLM Software NX 7.0”, Develop3d Magazine, print issue, November 2009, the section “issue management” describes the use of Siemens “PLM's NX Check-Mate” product which runs checks on a HD3D (“High Definition Information for Product Development”) model and returns a visual list of issues that it finds. Issues can be small faces that do not match Finite Element Analysis (FEA) requirements. Issues are identified through automated checks and the system assigns it to the person or team responsible by issuing a change request to a further software system.